xref: /linux-6.15/include/linux/gfp.h (revision 2b8232ce)
1 #ifndef __LINUX_GFP_H
2 #define __LINUX_GFP_H
3 
4 #include <linux/mmzone.h>
5 #include <linux/stddef.h>
6 #include <linux/linkage.h>
7 
8 struct vm_area_struct;
9 
10 /*
11  * GFP bitmasks..
12  *
13  * Zone modifiers (see linux/mmzone.h - low three bits)
14  *
15  * Do not put any conditional on these. If necessary modify the definitions
16  * without the underscores and use the consistently. The definitions here may
17  * be used in bit comparisons.
18  */
19 #define __GFP_DMA	((__force gfp_t)0x01u)
20 #define __GFP_HIGHMEM	((__force gfp_t)0x02u)
21 #define __GFP_DMA32	((__force gfp_t)0x04u)
22 
23 /*
24  * Action modifiers - doesn't change the zoning
25  *
26  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
27  * _might_ fail.  This depends upon the particular VM implementation.
28  *
29  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
30  * cannot handle allocation failures.
31  *
32  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
33  *
34  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
35  * mechanism or reclaimed
36  */
37 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
38 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
39 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
40 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
41 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
42 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
43 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
44 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
45 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
46 #define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
47 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
48 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
49 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
50 #define __GFP_THISNODE	((__force gfp_t)0x40000u)/* No fallback, no policies */
51 #define __GFP_MOVABLE	((__force gfp_t)0x80000u) /* Page is movable */
52 
53 #define __GFP_BITS_SHIFT 20	/* Room for 20 __GFP_FOO bits */
54 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
55 
56 /* if you forget to add the bitmask here kernel will crash, period */
57 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
58 			__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
59 			__GFP_NOFAIL|__GFP_NORETRY|__GFP_COMP| \
60 			__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE| \
61 			__GFP_MOVABLE)
62 
63 /* This equals 0, but use constants in case they ever change */
64 #define GFP_NOWAIT	(GFP_ATOMIC & ~__GFP_HIGH)
65 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
66 #define GFP_ATOMIC	(__GFP_HIGH)
67 #define GFP_NOIO	(__GFP_WAIT)
68 #define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
69 #define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
70 #define GFP_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
71 #define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
72 			 __GFP_HIGHMEM)
73 #define GFP_HIGHUSER_MOVABLE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
74 				 __GFP_HARDWALL | __GFP_HIGHMEM | \
75 				 __GFP_MOVABLE)
76 #define GFP_NOFS_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
77 #define GFP_USER_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
78 				 __GFP_HARDWALL | __GFP_MOVABLE)
79 #define GFP_HIGHUSER_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
80 				 __GFP_HARDWALL | __GFP_HIGHMEM | \
81 				 __GFP_MOVABLE)
82 
83 #ifdef CONFIG_NUMA
84 #define GFP_THISNODE	(__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
85 #else
86 #define GFP_THISNODE	((__force gfp_t)0)
87 #endif
88 
89 
90 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
91    platforms, used as appropriate on others */
92 
93 #define GFP_DMA		__GFP_DMA
94 
95 /* 4GB DMA on some platforms */
96 #define GFP_DMA32	__GFP_DMA32
97 
98 
99 static inline enum zone_type gfp_zone(gfp_t flags)
100 {
101 #ifdef CONFIG_ZONE_DMA
102 	if (flags & __GFP_DMA)
103 		return ZONE_DMA;
104 #endif
105 #ifdef CONFIG_ZONE_DMA32
106 	if (flags & __GFP_DMA32)
107 		return ZONE_DMA32;
108 #endif
109 	if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
110 			(__GFP_HIGHMEM | __GFP_MOVABLE))
111 		return ZONE_MOVABLE;
112 #ifdef CONFIG_HIGHMEM
113 	if (flags & __GFP_HIGHMEM)
114 		return ZONE_HIGHMEM;
115 #endif
116 	return ZONE_NORMAL;
117 }
118 
119 /*
120  * There is only one page-allocator function, and two main namespaces to
121  * it. The alloc_page*() variants return 'struct page *' and as such
122  * can allocate highmem pages, the *get*page*() variants return
123  * virtual kernel addresses to the allocated page(s).
124  */
125 
126 /*
127  * We get the zone list from the current node and the gfp_mask.
128  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
129  *
130  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
131  * optimized to &contig_page_data at compile-time.
132  */
133 
134 #ifndef HAVE_ARCH_FREE_PAGE
135 static inline void arch_free_page(struct page *page, int order) { }
136 #endif
137 #ifndef HAVE_ARCH_ALLOC_PAGE
138 static inline void arch_alloc_page(struct page *page, int order) { }
139 #endif
140 
141 extern struct page *
142 FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
143 
144 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
145 						unsigned int order)
146 {
147 	if (unlikely(order >= MAX_ORDER))
148 		return NULL;
149 
150 	/* Unknown node is current node */
151 	if (nid < 0)
152 		nid = numa_node_id();
153 
154 	return __alloc_pages(gfp_mask, order,
155 		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
156 }
157 
158 #ifdef CONFIG_NUMA
159 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
160 
161 static inline struct page *
162 alloc_pages(gfp_t gfp_mask, unsigned int order)
163 {
164 	if (unlikely(order >= MAX_ORDER))
165 		return NULL;
166 
167 	return alloc_pages_current(gfp_mask, order);
168 }
169 extern struct page *alloc_page_vma(gfp_t gfp_mask,
170 			struct vm_area_struct *vma, unsigned long addr);
171 #else
172 #define alloc_pages(gfp_mask, order) \
173 		alloc_pages_node(numa_node_id(), gfp_mask, order)
174 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
175 #endif
176 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
177 
178 extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
179 extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
180 
181 #define __get_free_page(gfp_mask) \
182 		__get_free_pages((gfp_mask),0)
183 
184 #define __get_dma_pages(gfp_mask, order) \
185 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
186 
187 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
188 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
189 extern void FASTCALL(free_hot_page(struct page *page));
190 extern void FASTCALL(free_cold_page(struct page *page));
191 
192 #define __free_page(page) __free_pages((page), 0)
193 #define free_page(addr) free_pages((addr),0)
194 
195 void page_alloc_init(void);
196 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
197 
198 #endif /* __LINUX_GFP_H */
199